Pressure affected circuit controller



Sept. 6,1932. P. F. SHlVER$ I 1,875,669

PRESSURE AFFECTED CIRCUIT CONTROLLER I I Filed Sept. 22. 1930 I N VEN TOR. 10 Paul 171571176217 A TTORNEYS Patented Sept; 6, 1932 UNITED STATES PATENT OFFICE PAUL F. SHIVEBS, OF WABASH, INDIANA, ASSIGNOR TO MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF DELA- WARE PRESSURE AFFECTED CIRCUIT CONTROLLER Application filed September 22, 1930. Serial No. 483,463.

The object of my invention is to produce an 'eflicient device by means of which variations in pressure, obtained from any desired source, either as a result of variations in tem- I perature upon an expansible medium or directly by variations in the pressure at a desired source, or otherwise, may be utilized to vary electrical circuit conditions of a circuit-controlling element.

More specifically the object of my invention is to provide certaindetails of structure by means of which the parts may be adjusted so as to produce the desired circuit changes at desired points in the pressure-variation 1 cycle and other details of structure whereby the parts are protected from distortion by undue stresses.

The accompanying drawing illustrates my invention: Fig. 1 is a side elevation of an apparatus embodying my invention;

Fig. 2 is a partial side elevation and partial medial axial section in a plane at right an les to the lane of Fig. 1; and

ig. 3 is a ragmentary section on a plane parallel with the plane of Fig. 1 just behind the lever 55.

In the drawing 10 indicates a pressure cup provided with a nipple 11 for attachment to a desired pressure source and provided with a cover 12 which is formed in part of a collapsible and expansible element 13 capable of responding to variations of pressure within the cup 10. 4

The end wall 13' of element 13 is provided with an axial boss 14 having an axial pocket 15.

Secured to the top of the cup 10 is a frame 20 provided at its upper end with an internally threaded boss 21 in axial alignment with boss 14 and threaded in this boss is an adjustable abutment 22 having an annular flange 23 provided with a plurality of radial 45 pockets 24 for the reception of a pin by means of which the abutment 22 may be readily turned and thus adjusted.

Seated in pocket 15 is the lower end of a pin 25 the upper end of which is journalled in the bore of abutment 22 and provided with a cross slot 26 for the reception of a screw driver.

Pin 25 at an intermediate point is threaded at 27 to receive a spring-abutment 28.

slot 38 being open for convenience of assembly and receiving pin 30.

Projected through slot 37 and slidable laterally therein, is a threaded shank 40 provided with a head 41 transversely slotted at 42. The end of shank 40 is threaded into an arm 43 which, at its outer end, is perforated to receive an eccentric pin 44 carried at the inner end of a head 45 j ournalled in an opening 46 in bridge piece 36 and provided at its outer end with a cross slot 47, the arrangement being such that rotation of head 45 will operate, through arm 43, to adjust shank 4O laterally in slot 37. Sleeved upon shank 40 outside of bridge piece 36, and engaging the same adjacent slot 37, is a spacer 50 engaged by a shoulder on shank 40.

Sleeved on pin 40 is a sleeve 51 carried by a bell-crank lever 55 slotted at 56 to permit pin 30 to project freely therethrough. The short arm of lever 55 carries a pin 57 and the long arm carries a pin 58.

J ournalled on sleeve 51 are two levers 60 and 61 adjacent ends of which are connected by a tension spring 62. One arm of lever 61 is projected so as to overlie pins 30 and 57 and one arm of lever 60 is projected to underlie pins 30 and 57, the said arms. of levers 60 and 61 being preferably brought into a common plane relative to said pins 30 and 57.

J ournalled upon pin 58 are two fingers 64 and 65 provided with depending tails 64 and 65' respectively, provided respectively with projections 64 and 65" arranged to yieldingly engage a serrated flange 66 of a graduated segment 67 attached to the long arm of lever 55. Tails 64 and 65 are provided respectively with finger pieces 64 and 65' by means of which they may be readily manipulated.

Secured to the upper end of the frame 20 is a bracket 70 u on which is journalled, on pin 71, a spring 0 ip 72 adapted to receive and support a mercury tube contactor 73 which is the circuit-controlling element. Clip 72 is provided with a pin 74 projected between fingers 64 and 65.

The circuit wires 75 from the tube 73 are carried down through an eye 76, conveniently carried by pin 71, to a terminal plate 77 secured to the rear of frame 20.

The parts above head 12 may be enclosed and protected by a removable cover 78, indicated in dotted lines in Fig. 1.

In operation, movement of head 13, in response to variations of the pressure established in cup 10, moves pin 30 which, acting through the pressure-scissors 606162, acts upon pin 57 to swing lever and thus shift fingers 64 and 65 relative to pin 74, ultimately, through said pin 74, to rock clip 72 upon its pivotal support 71 and thus tilt the mercury tube to modify the circuits of which wires 75 form parts.

\Vith the parts in the relative positions shown in Fig. 1 upward movement of pin 30 will transmit force through lever 61, spring 62 and lever 60 to pin 57 so as to swing fingers 64 and to the right. Suflicient upward movement of pin 30 will bring finger 65 into engagement with pin 74 to tilt clip 72 toward the right and when pin 74 passes over the vertical center of pin 71 the tube 73 will continue by gravity to its ultimate extreme in that direction. If the upward movement of pin 30 continues, further movement of finger 65 to the right being obstructed by the limitations of further movement of clip 72, lever 61 will yield against the action of spring 62 and damage to the parts will be prevented.

On the return downward movement of pin 30, due to a decrease of pressure within cup 10 and the action of spring 31, lever 55 will be swung to the left so as to ultimately cause a tilting of tube 73 to the position shown in Fig. 1 whereupon further downward movement of pin 30 will shift the left-hand end of lever 60 downwardly against the action of spring 62, thus protecting the parts from strain.

Adjustment of fingers 64 and 65 upon their pivot determines the times of rocking of the clip 72 relative to the position of pin 30 so that a. circuit change may be obtained at any desired maximum and minimum within the range of the instrument.

Adjustment of abutment 22 varies the strength of spring 31 upon head 13. An ad justment of pin 25 positions pin 30 relative to head 13.

Rotation of head 45 shifts the axis of lever 55 relative to pin 30 and thus lengthens or shortens the efliective leverage of pin 30 upon lever 55. This adjustment is attained by first loosening screw 40-41, then rotating head 45, and then clamping arm 43 and sleeve 40 upon bridge 36 so as to form a firm pivotal support for lever 55, said lever and the pressure scis-' sors (SO-61, remaining freely rotatable upon sleeve 51. I

When the instrument is placed in service under a pressure about midway of the range of the action of the instrument pins 30 and 57 are in substantial horizontal alignment with slot 37 and in the plane of pin 40 and the long arm of lever 55 is in the vertical plane of pivot 71 and pin 74 in its medial position so that adjustment of pin 40 in slot 37, by means of head 45, permits an accurate placement of the long arm of lever 55 relative to the medial position of the mercury tube.

When fingers 64 and 65 may be as closely or as distantly spaced as desired and the gap between these fingers may be either in the line of the long arm of lever 55 or to either side of that line. Consequently the desired tilting of tube 7 3 may be obtained more or less promptly following pressure reversal and at any desired maximum and minimum within the range of the instrument.

The mercury in tube 73 acts to bias said tube in either direction from the medial position of the tube and thus carry it to the limits of its movement independently of the finger actuation.

When the abutment 22 has been adjusted at the factory, it is set in place by means of the set screw 80 which is then sealed by sealing wire 81 passed around the frame 20.

I claim as my invention:

1. A circuit-controller comprising a shiftable terminal element and a projection associated therewith, a. shiftable arm, a pair of fingers independently medially pivoted on said arm with one pair of ends of said fingers straddling said projection, and means carried by the arm for engaging and retaining the opposite ends of said fingers in adjusted position.

2. A circuit-controller comprising a shiftable terminal element and a projection associated therewith, a lever, a pair of fingers independently adjustable on one arm of said lever and straddling said projection, a pair of spring-urged fingers each having a oneway engagement with the other arm of said lever, an actuator pin arranged between said fingers and having a one-way engagement with each finger, and means for shifting said pin in either direction from a medial position.

3. A circuit-controller of the character specified in claim 2 wherein the lever has a laterally adjustable fulcrum.

4. In a circuit-controller of the character specified in claim 2, a slotted bridge piece, a

threaded pin projected through said slot, a head rotatably mounted in said bridge piece and provided with an eccentric pin, an arm pivoted on said eccentric pin and receiving said threaded pin, said arm engaging one face of the bridge piece, means associated with the threaded pin for engaging the bridge piece in opposition to said last-mentioned arm, the finger-carrying lever and the spring urged 1 fingers being freely pivoted about said threaded pin.

5. A pressure-afiected/ circuit a controller comprising a pressure cup having a yieldable wall, amercury tube circuit controller,

a rockable holder for said circuit controller having a limited range of movement, a lever supported on the pressure cup, a pair of independently adjustable fingers pivoted on one arm of said lever and straddling a projecting portion of the tube holder, means for holding said fingers in adjusted position, and a two-way-yielding connection between said lever and the movable wall of the pressure cup.

6. A pressure-afiected circuit controller comprising a pressure cup having a yieldable wall, a mercury tube circuit controller, a rockable holder for said circuitcontroller having a limited range of movement, a lever supported on the pressure cup, a pair of independently adjustable fingers carried by one armof said lever and straddling a projecting portion of the tube holder, means for holding said fingers in adjusted position, a

j pin carried by the other end of said lever, a

pair of spring-urged fingers concentric with said-lever and straddling said lever pin to have one-way engagement therewith, and a pin actuated by the movable wall of the pressure chamber and projected between said spring-urged fingers and having a one-way engagement with each of said fingers. I

7. A pressure-afiected circuit controller comprising a pressure cup having a movable wall responsive to ressure variations within the cup, a spring a utment adjustable in the line of movement of the yieldable wall and provided with a central bore a pin j ournaled in the bore of said sprin abutment and rotatably engaging the yiel able wall and having a threaded portion, a springabutment threaded upon said threaded portion, a spring interposed between said abutments, a pin carried by said second abutment, a shiftable circuit-controlling element, and intermediate connections between said circuit controlling element and said last-mentioned pin. In witness whereof,'I have hereunto set my hand at Wabash, Indiana, this 19 day of Se tember, A. 1). one thousand nine hundred thirty.

PAUL F. SHIV'ERS. 

